Rubber sole for boots and shoes.



A. D. WARNER.

RPBBEB SOLE FOR BOOTS AND SHOES. APPLICATION FILED APB.16.1909.

953,077. 1 Patented Mar.29, 1910.

awuewtoc mic M1213 2 g for boots and shoes.

ADNA. n. ARNER, or MisH-Awam, INDIANA.

RUBBER SOLE ron. BOOTS AND snons.

Specification of Letters Patent.

Patented Mar. 29, 1910.

Application filed April 16, 1909. Serial No, 490,222.

To all whom it may concern:

Beit known that-I, ADNA D. WARNER, a citizen of the United States, residing in Mishawaka, county of St. Joseph, State'of Indiana, have invented a certain new and useful Improvement in Rubber Soles for Boots or Shoes, of which the followingis a specification.

In a pendin application of even date herewith Seria l\umber 490,223 I. have claimed a certain improved method or proce' for making rubber fabric and particulftry for the production .of rubber soles The present application relates to soles made in accordance with the process set forth in said cO-pend'ing application.

The principal advantage found in the soles herein claimed arefirst: superior durability as compared with former soles made of the same thickness andmaterialsecond: no increase incostof production third: the soles are made and ap liedby existing types of machinery and t erefore their manufacture involves no .change in existing plants-fourth: a thicker sole is produclble without impairing the quality of the material-fifth: the various portions of the sole are individually adapted to the special wearing stresses to whichthey are respectively subjected. These advantages result from two principal features of im- 'provement which I prefer to combine as hereinafter described, but which may be used independently with good results. The

first of these features, which has reference to the mode of relating what I term the line of rolling of the material in different layers, has for its object the prevention of breaking or checking in the fabric, and the distribution of the material so as to adapt various portions of the sole to their individual requirements. The second feature, having reference to cold rolling of the sheets While building'up the fabric, has for its object the entire avoidance of air cells in the completed fabric, and makes it possible (especially in the preferred arrangement e scribed) to build up very thick soles without danger of imperfections.

It is obviously desirable to make rubber soles on boots and shoes as thick as possible, consistently with comfort in wearing them. The life of such soles is of course roughly proportional to such thickness, other thing's being equal. But it is found in practice that the thicker a single sheet of rubber is rolled in calendering the greater is the proportion of air cells, and as these cells are opened by process of Wear, they absorb dirt and water and cause rapid disintegration of the material. On the other hand, Where soles are built up of separate calendered sheets united by cement, the utmost care cannot prevent formation of similar cells, due to the volatile ,ingredient of the rubber cement (generally benzene) permeating the mass of the rubber and producing a spongy texture by its expansion.

I have discovered that separate calendered sheets of green or uncured rubber may be united perfectly by rollingv cold under increased pressure as compared with the calendering pressure, and that, where this process is resorted to, practically all spongy texture is done away with.

I have further discovered that by the use of this process, the eculiar internal structure of the materia originally caused by the calendering rolls is not materially dis turbed. This discovery has rendered possible the arrangement of the various sheets or layers as hereinafter described without sacrificing any of the advantages pointed out.

The improved sole in its preferred form,

will be described with reference to the accompanying drawings wherein- Figure 1 is a side elevation of one form of the improved sole showing the laminae or some of them separated at one end for greater distinctn'ess, Fi 2 is a plan view of the under or outer face of sald sole as completed, and Fig. 3 is aside elevation as com leted.

W here rubber compounds are formed into sheets by passing them between hot calendering rol's the internal structure is modified, and I have found that the following qualities are observable:

First: the tensile strength is reater in the direction in which the rolling as occurred. This direction I have termed the line 0 rolling.

Second: the elasticity or resiliency is greater at right angles to this direction.

Third: the tendency to split or check is greater when a sheet is bent on curves whose axis is parallel to the line of rolling (in.

other words across the sheet) than when bent at right angles to this direction.

I have also discovered that where calen with this dered sheets of rubber compound are united by cold rolling as above described, thisinternal structure is not interfered with by 'the excessive pressure necessary in connection process. Furthermore I have found by practical commercial use that, by uniting sheets with their lines of rolling making material angles the one with the other, the, advantageous qualities belonging to each direction of the lines may-be united as hereinafter more fully set forth.

The particular sole shown as anexample in the drawings is built up as follows: The plain sole 10, intended to receive the heel and tap and to be. joined to the uppers, is composed, of a number of laminae or sheets 11 and 12. In the particular instance illustrated these are two in number although more may be used if desired without departingfrom my invention. I prefer to form the tap of a number of intermediate laminae or sheets 13 and 14:, upon which is placed a thicker outside tap" sole 15, preferably corrugated, as shown, in a well known manner.

In uslng a boot 'or shoe, the act of walking or running subjects the entire sole to repeated bending strains or curves-whose axis lies across the shoe or boot. Hitherto, where soles were built up of separate sheets, they have been placed with the lines of rolling of all the sheets'across the shoe. The result has been a very general tendency to check or split across the sole. It is obvious that 'the greater degree of bending will come in the lowermost layer 15 and therefore the arrangement of material. should be such as to afford the maximum elasticity atthis part of the sole. As I have pointed out above, this is afforded by placing the line of rolling across the sole at right angles, and I therefore prefer to so place the corrugated layer 15., I have discovered, however, that the tendency to check or split -wh1ch would otherwise exist in a layerso placed, may be overcome by uniting with the layer 15 other layers, as 11, 12, 1 3 and 14:, whose lines of rolling are longitudinal with respect to the sole. Broadly speaking this may be accomplished in any suitable manner (including the use'of 'cement) but I prefer the processes described below. The arrangement described affords. the tensile strength and the prevention of checking due to longitudinal lines of rolling, while also giving the elasticity in the under portion of the sole due to transverse lines. Accordingly I have found that shoes and boots provided with rubber soles made as above described ex hibit increased 'wearin qualities without sensible diminutionof e asticity. Moreover tearing or splitting through the whole sole is entirely prevented.

It is within the scopeof this invention to place the alternate sheets with their lines of rolling crossing each other, or any other arrangement of crossed lines of rolling might be employed Without departing from this 1nvention. Where'sheets are thus joined with lines of rolling crossed, inorder to avoid distortion or change of molecular arrangement, as well as to prevent the formation of air cells within the sole. I prefer to unite the sheets by running them together cold, in uncured condition through laminating rollers of a well known type, having a vielding pressure caused by the use of weights or springs. The weight or pressure used 1s four or five times as great as that employed where mere cementing is to be accomplished, or where sheets are united hot.

-In building up' the particular sole illustrated, I take two sheets 11 and 12 and unite them (or a greaternumber if desired) by the ordinary process of warm rolling with their'original rolling lines parallel. From these sheets so united properly shaped pieces indicated by the outermost outline in Fig. 2 are constructed in any well known manner. The sheets 13 and-14 are united in the same manner as 11 and 12 with their original rolling lines parallel, and to this double material is uhlted the outermost corrugated layer or layers 15 with its or"their line of rolling at right angles to those of the layers 13and 14. This last named junction is cf;

fected by the cold rolling process above described.

From the material produced as last above described properly shaped pieces to form the taps are cut out, and these may be jomed to the lain sole (composed of the layers 11 and 12 by rollin col impurity being 'rst removed, preferably by benzene. This completes the sole w th the exception of applying 'the heel, WlllCh can be accomplished in any convenlent way. In my claims the term rubber applies to any of the well known compounds to which that ,term is commercially ap 116d, capable of treatment as above describe and the word sole, save when otherwlse limited, covers whatever maybe joined to the uppers of a boot or shoe beneath the same, whether or not a tap or heel or both be mcluded.

In my claims, the expression united 1ntegrally indicates union of adjacent sheets without the intervention of foreign material such as the benzene or other volatile constituent of rubber cement which causes sponginess-and consequent weakening of the fabric.

IV hat I claim is- 1. A sole for boots or shoes comprlslng a plurality of calendered sheets of rubber snperposed and united so that some of sa1d sheets are placed with the line of rolllng lying longitudinally of the sole to attain maximum tensile resistance, and some are placed with the line of rolling across the sole any grease or other perposed andunited integrally with the line first named sheets, with lines of rolling runto attain maximum resilience, as described;

2. A sole for boots or shoes comprising a plurality of calendered sheets of rubber susubstantially I of rolling of one or more of said sheets set across the line of rolling of others, substantially as described. a

3. A sole for boots or shoes comprising interior sheets of calendered rubber united with parallel lines of rolling lying longitudinally of the sole and one or more exterior sheets of calendered rubber united to said ning across the sole, substantially as described.

4. A sole for boots or shoes comprising a plurality of calendered sheets of rubber superposed and united integrally with parallel one or more exterior sheets of calendered rubber united integrally to said first named sheets, with lines of rolling running across the sole, substantially as described.

5. A sole for boots or shoes comprising an interior plain sole com osed of sheets of calendered rubber unite with parallel lines of rolling lying lon itudinally of the sole; in combination wit a tap sole united to said plain sole and composed of similar sheets of calendered rubber united with parallel lines of rolling lying longitudinally of the sole and one or more exterior sheets of calendered rubber united to said latter united sheets with lines, of rolling running across the sole, substantially as described.

6. A sole for boots or shoes comprising an interior plain sole composed of sheets .of calendered rubber united integrally with parallel lines of rolling lying longitudinally of the sole; in combination with a tap sole united to said plain sole and composed of similar sheets of calendered rubber united integrally with arallel lines of rolling lying ongitudinal y of the sole and one or more exterior sheets of calendered rubber united inte rally to said latter united sheets with lines of rolling running across the sole, substantially as described.

ADNA D. WARNER.

Witnesses:

H. S. MACKAYE, M. A. BUTLER. 

